Aquarium simulator
Keep a virtual tank with a real nitrogen cycle. Set it up, cycle it, feed your fish, change the water and stock it, and see what happens when you rush. Mistakes here cost nothing.
Runs in your browser, nothing to install. Your tank saves on this device, and time keeps passing while you’re away.
What you’ll learn
Cycling a new tankWatch ammonia, nitrite and nitrate rise and fall as the filter bacteria grow, day by day.Why you add fish slowlyAdd too many fish to a young tank and the bacteria can't keep up. Ammonia climbs on the test kit before the fish show it.Water changesEvery 30% you change removes 30% of what's dissolved. See exactly how a weekly change keeps nitrate down.Plants and lightGrowing plants soak up waste and add oxygen while the lights are on; too much light grows algae instead.
How it relates to the rest of this site
The game simulates how a tank behaves over time: bacteria growth, waste, oxygen and plant uptake. Its numbers are a model, tuned to behave like a real tank, not measured facts. For checked care facts and tank mate verdicts, use the species guides and the compatibility checker. Terms in the game that we cover in a guide link back here for the full explanation.